The United States is continuing to reinforce its military forces in Europe as planned, irrespective of President-elect Donald Trump's future intentions, the Pentagon said Thursday.

Trump, who will take office in January, raised serious concerns in Europe by promising during his campaign that US engagement in NATO under his presidency would be conditional on members' payments to the alliance.

Washington is scheduled to start deploying an additional combat brigade in Europe in February to bring the number of brigades on the continent to three.

The plan is part of an effort to boost Eastern European defenses against possible attack by Russia.